From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265169AbTLZL4z (ORCPT ); Fri, 26 Dec 2003 06:56:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265171AbTLZL4z (ORCPT ); Fri, 26 Dec 2003 06:56:55 -0500 Received: from holomorphy.com ([199.26.172.102]:18860 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S265169AbTLZL4y (ORCPT ); Fri, 26 Dec 2003 06:56:54 -0500 Date: Fri, 26 Dec 2003 03:56:47 -0800 From: William Lee Irwin III To: Nick Craig-Wood Cc: linux-kernel@vger.kernel.org, Rohit Seth Subject: Re: 2.6.0 Huge pages not working as expected Message-ID: <20031226115647.GH27687@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Nick Craig-Wood , linux-kernel@vger.kernel.org, Rohit Seth References: <20031226105433.GA25970@axis.demon.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20031226105433.GA25970@axis.demon.co.uk> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 26, 2003 at 10:54:33AM +0000, Nick Craig-Wood wrote: > I wrote a little test program to show the benefits of huge pages by > reducing TLB thrashing - it fills up 16 MB with sequential numbers > then adds them with different strides - very much the sort of thing > FFTs do. However huge pages show a performance decrease not increase > for large strides! For smaller ones there is a small speedup. > I've been testing on > processor : 0 > vendor_id : GenuineIntel > cpu family : 6 > model : 8 > model name : Pentium III (Coppermine) P-III has something like 2 TLB entries usable for large pages. I recommend trying this again on a P-IV. -- wli